This invention relates to an instrument for measuring the time integral of the solar energy flux falling on a flat surface. The integrator integrates the direct and diffuse radiation power of solar energy impinging on the instruments front plane.
An integrating device of this type is useful for solar energy applications since the solar energy falling on a flat surface depends not only on the geographical location and the direction of the incoming radiation, but also to a large extent upon the weather conditions, the environment (such as mountains, trees, snow, water, and pollution), as well as the state of the collecting surface. Some of these parameters may also change continuously with time (seasons etc.).
It is very difficult if not impossible to take into account all these parameters for computing the correct energy input from the rare existing "hours of sun" data; consequently, there is need for a solar energy flux integrator which can be used in exactly the same way, and as easily, as the numerous rain gauges distributed all over the world.
Conventional solar energy meters and integrators, such as pyrhelio-meters and integrating pyranometers, are very precise, costly instruments which need skilled technicians for reading and service. They are heavy, bulky, devices and need power supplies.